The present invention relates generally to catheters for performing medical procedures. More particularly, the present invention relates to methods and devices for managing a portion of the catheter which extends from the body of a patient under operating room conditions (e.g., while the physician is wearing surgical gloves).
Intravascular catheters are currently utilized in a wide variety of minimally invasive medical procedures. Generally, an intravascular catheter enables a physician to remotely perform a medical procedure by inserting the catheter into the vascular system of the patient at an easily accessible location and navigating the tip of the catheter to a desirable target site. By this method, virtually any target site in the patient""s vascular system may be remotely accessed, including the coronary, cerebral, and peripheral vasculature.
Intravascular catheters are often used in conjunction with a guidewire. When this is the case, the guidewire may be advanced through the patient""s vasculature until its distal tip has reached a desired target location. In many cases, the guidewires path through the vascular system will be tortuous, requiring the guidewire to change direction many times. By pushing and rotating the proximal end of the guidewire outside of the patient, the physician is able to direct the distal end of the guidewire to the desired target site. Once the distal portion of the guidewire is proximate the desired location, the catheter may be threaded onto the guidewire and urged distally until the distal end of the catheter is proximate the target location. The catheter often has been unpackaged and prepared for use prior to this point. After being prepared, but prior to actual use, the catheter must be laid out and kept sterile without being put back in the original package. It is often useful to be able to coil the catheter in order to facilitate handling and save space either laying out or hanging up the catheter, because of the length of the catheter (typically over 1 meter long).
Typically, the catheter enters the patient""s vasculature at a convenient location such as a blood vessel in the neck or near the groin. Once the distal portion of the catheter has entered the patient""s vascular system, the physician may urge the distal tip forward by applying longitudinal forces to the proximal portion of the catheter. In order for the catheter to effectively communicate these longitudinal forces and resist kinking, the proximal portion of many intravascular catheters is made relatively stiff.
The path taken by a catheter through the vascular system is often tortuous, requiring the catheter to change direction frequently. In some cases, it may even be necessary for the catheter to double back on itself. In order for the catheter to conform to a patient""s tortuous vascular system, the distal portion of many intravascular catheters is very flexible or floppy.
The distance between the access site and the target site is often in excess of 100 cm. In order to assure that the physician will have access to the proximal end of the catheter when the distal end of the catheter is disposed near the target site, many intravascular catheters are relatively long. For example, a catheter shaft may have a length from about 70 cm to about 150 cm.
While the distal end of an intravascular catheter is being advanced into the body of a patient, a proximal portion of the catheter extends outside the body of the patient. During this procedure, care must be taken to assure that the proximal portion of the catheter remains inside the sterile field. If the proximal portion of the catheter were allowed to touch a non-sterile surface (e.g., the floor), the contaminated intravascular catheter would need to be discarded and replaced. The discarding of a contaminated intravascular catheter and replacing it with a new, sterile one adds expense to the surgical procedure. More critically, the replacement procedure adds time to the procedure. In some cases, the duration of the procedure may be substantially extended. For example, a dilation catheter may need to be xe2x80x9cpreppedxe2x80x9d before it is used. This preparation procedure may include the time consuming steps of evacuating air from the device and back filling the device with a fluid. A longer procedure is inherently more expensive; but more importantly, a longer procedure may present a greater risk to the patient.
Intravascular catheters may be utilized for various diagnostic and/or therapeutic purposes. One example of a therapeutic use for an intravascular catheter is percutaneous transluminal angioplasty (PTA). An angioplasty procedure typically involves the use of a dilation catheter. The dilation catheter is typically advanced through the vasculature of a patient until a balloon portion of the dilation catheter is positioned proximate the restriction in the diseased vessel. The balloon is then inflated, and the restriction in the vessel is opened. In some cases, multiple restrictions may be opened utilizing a single dilation catheter. When this is the case, the dilation catheter may be partially or completely withdrawn from the body of the patient. When the catheter is withdrawn, care must be taken to assure that the catheter remains inside the sterile field.
As described above, the proximal portion of many intravascular catheters is quite stiff. Because the distal portion of these catheters is typically stiff, intravascular catheters are biased to assume a straight shape and will not readily remain in a coiled configuration. In some cases, it is necessary for an assistant to hold the proximal portion of the catheter while it is being introduced or withdrawn from a patient. The assistant may manually coil the proximal portion of the intravascular catheter and hold it in a coiled configuration. The addition of an assistant to the surgical environment to hold the catheter proximal portion is quite costly. The physicians and other personnel involved in a surgical procedure also must wear surgical gloves for the duration of the procedure. In many cases, a xe2x80x9cdouble-glovingxe2x80x9d procedure is used. The wearing of surgical gloves inhibits the surgeon""s ability to manipulate small objects.
The present invention relates generally to catheters for performing medical procedures. More particularly, the present invention relates to methods and devices for managing a portion of the catheter which is extending from the body of the patient under operating room conditions (e.g., a sterile field while the physician is wearing surgical gloves). Methods and devices in accordance with the present invention may also be utilized to manage a shaft of the catheter after the catheter is unpacked, but prior to use in a surgical procedure.
A catheter in accordance with one embodiment of the present invention includes a catheter shaft having a proximal end and a distal end, and a keeper fixed to the catheter proximate the proximal end thereof. The keeper includes one or more inside surfaces defining a channel which is adapted to entrap a straight portion of the catheter shaft. The keeper also includes a passageway which is adapted to allow a portion of the catheter shaft which has been urged into a curved shape to pass into the channel of the keeper.
In one method in accordance with the present invention, the catheter shaft may be urged into a curved shape by exerting one or more pushing forces on the catheter shaft. For example, a physician may push on the catheter shaft with a gloved thumb. In another method in accordance with the present invention, a loop may be formed with the catheter shaft. In this method, a portion of the loop may be passed through the passageway and into the channel of the keeper. This embodiment of the present invention enables the physician to capture a portion of the shaft within the keeper without manipulating or deforming the keeper. An advantage of this method is that a physician is able to perform the required steps easily, even while wearing two pairs of surgical gloves.
A catheter in accordance with an additional embodiment of the present invention includes a catheter shaft having a proximal end and a distal end, and a keeper fixed to the catheter proximate a proximal end thereof. The keeper includes a first arm and a second arm defining an aperture. In one method in accordance with the present invention, the catheter shaft is placed in a first position between the first arm and the second arm. The catheter shaft may be twisted and moved to a second position within the aperture defined by the first arm and the second arm. Preferably, the first arm and the second arm releasably trap the catheter shaft when it is disposed within the aperture of the keeper. It should be noted that a physician may position the catheter shaft in the first position and the second position without manipulating the keeper directly. For example, a physician may grasp a hub of the catheter in one hand and a portion of the catheter shaft in a second hand. The catheter shaft has sufficient length that it may be grasped between the palm and fingers of a hand. The keeper of this embodiment allows a physician to capture a portion of the catheter shaft easily, even when wearing two pairs of surgical gloves.
A catheter in accordance with yet another embodiment of the present invention includes a catheter shaft having a proximal end and a distal end. The catheter also includes a hub and a keeper which is fixed to the hub. In a preferred embodiment, the keeper is adapted to clip onto the hub. An advantage of this embodiment is that the keeper can be used in conjunction with existing catheters with no modification to the hub. Embodiments of the catheter have also been envisioned in which the keeper and the hub are formed from the same material, for example, by injection molding. The keeper includes one or more tabs. A portion of the catheter shaft may be urged between the tab and the hub.